Who do I go to from the (C)AGW side to read substantiated, analytical counter arguments to what is posted here on CA

When you find this “Holy Grail” site, please come back and tell us where it is. I’ve been searching for it for over 10 years now.

]]>By: John Ahttps://climateaudit.org/2006/01/28/rutherford-mann-et-al-2005/#comment-43061
Sun, 30 Nov 2008 08:02:55 +0000http://www.climateaudit.org/?p=513#comment-43061Just sent this comment to RC but I’m doubtful this will ever see the light of day there:

===========================================

We will, of course, be fascinated to find out in what peer-reviewed literature we will find the disconfirmation that “the Hockey Stick is discredited” – perhaps it will be the Ammann and Wahl so-called “Jesus Paper” (on the grounds that it has miraculously risen from the dead) where the brave authors invent their own statistical tests in order to acquit the Hockey Stick. These statistical tests have been heard of before in the standard statistical literature and, I’m willing to bet, never will be heard of again.

Will it be from Professor Edward Wegman? Nope. Here is a statistician of first rank and impeccable credentials who did the heavy lifting of dissecting the Hockey Stick. His verdict?

“Where we have commonality, I believe our report and the [NAS] panel essentially agree. We believe that our discussion together with the discussion from the NRC report should take the ‘centering’ issue off the table. [Mann’s] decentred methodology is simply incorrect mathematics …. I am baffled by the claim that the incorrect method doesn’t matter because the answer is correct anyway.
Method Wrong + Answer Correct = Bad Science.

The papers of Mann et al. in themselves are written in a confusing manner, making it difficult for the reader to discern the actual methodology and what uncertainty is actually associated with these reconstructions.

It is not clear that Dr. Mann and his associates even realized that their methodology was faulty at the time of writing the [Mann] paper.

We found MBH98 and MBH99 to be somewhat obscure and incomplete and the criticisms of MM03/05a/05b to be valid and compelling.”

But then what does he know? All Mann could do is what he always does with scientific criticism of his works – impugn the motives of the critics.

What of the NRC Report and Gerry North perhaps? Always willing to help out friends?

CHAIRMAN BARTON. … Dr. North, do you dispute the conclusions or the methodology of Dr. Wegman’s report?
DR. NORTH. No, we don’t. We don’t disagree with their criticism. In fact, pretty much the same thing is said in our report.

What about Peter Bloomfield?

Our committee reviewed the methodology used by Dr. Mann and his coworkers and we felt that some of the choices they made were inappropriate. We had much the same misgivings about his work that was documented at much greater length by Dr. Wegman.

What about statistical authorities on PCA and Mann’s use of it? “Bulldog” Tamino thought Ian Joliffe would approve of Mann’s exciting method, an effort which spectacularly rebounded when Joliffe demanded a retraction and an apology and ended with this:

I am by no means a climate change denier. My strong impressive is that the evidence rests on much much more than the hockey stick. It therefore seems crazy that the MBH hockey stick has been given such prominence and that a group of influential climate scientists have doggedly defended a piece of dubious statistics. Misrepresenting the views of an independent scientist does little for their case either. It gives ammunition to those who wish to discredit climate change research more generally. It is possible that there are good reasons for decentred PCA to be the technique of choice for some types of analyses and that it has some virtues that I have so far failed to grasp, but I remain sceptical.

So apart from Mann’s dogged insistence on never mentioning the words “McIntyre” or “McKitrick” and never, ever dealing with the substance of the criticisms made of his use of statistics by extremely well qualified scientists, we are no nearer to any explanation as to how the criticisms of the “Hockey Stick” have been discredited, except by repeating that they have been discredited over and over.

Someone here is in denial, and I don’t think its the climate realists. When will Mann deal with substance and not spin?

(a clear dig at CA) and to substantiate the claim that the criticism of the hockey stick would have “now” been discredited, they give links, via a wikipedia site, to articles that are from 2-4 years ago. As a highlight a posting on rc by Mann from December 2004 that refers to Rutherford [this study here] to prove McIntyre and McKitrick wrong. Is this really the best they can come up with 3-4 years later? Why are there no better counter arguments available on realclimate than the repetition of these age old assertions?

Counter-arguments of which they never commented on?

So to enquire: Where can you follow the *real* debate? With points and counter points and the requirement to substantiate your claims and admit errors? Does it exist? There must be thousands of climate scientists, surely some of them are engaging in productive discussions and debates?
Who do I go to from the (C)AGW side to read substantiated, analytical counter arguments to what is posted here on CA, to better understand the nature of this confrontation/disagreement over the credibility of paleoclimatic records and graphs?

And how alone is the Hockey Stick in it’s field of study? Is there a library of paleoclimatic graphs somewhere on the net that you can browse for a comparison?

It’s pretty depressing to go to the “other side”, and try to listen to their arguments, and end up here, Rutherford 2005.

]]>By: Niche Modeling » Simple Linear Regression of Rainfallhttps://climateaudit.org/2006/01/28/rutherford-mann-et-al-2005/#comment-43059
Mon, 17 Jul 2006 15:10:38 +0000http://www.climateaudit.org/?p=513#comment-43059[…] Here is the technical documentation of software SPLINA and SPLINB. The additive regression model appears to be a practical option for analysing spatially varying effects of several predictors on observed phenomena. It is attractive from the point of view of overcoming curse of dimension problems associated with the analysis of noisy multivariate data. Moreover its implementation is a straightforward extension of standard thin plate spline methodology. Splines are a standard technique well defined by statisticians and suitable for reconstruction of past climates from proxy records. Yet climate scientists associated with Michael Mann continue to develop ad hoc methodologies with questionable assumptions without the benefit of statisticians as criticised in the Wegman report. The lesson for successful prediction is like the old saw: brain surgery is not for do it yourselfers.Share and Enjoy:These icons link to social bookmarking sites where readers can share and discover new web pages. […]
]]>By: Jeff Normanhttps://climateaudit.org/2006/01/28/rutherford-mann-et-al-2005/#comment-43058
Thu, 02 Feb 2006 07:06:21 +0000http://www.climateaudit.org/?p=513#comment-43058Re #30,

Bryan Leyland,

I too have have considered the Mauri arrival in New Zealand to be strangely coincidental with a MWP. I like the calmer ocean hypothesis.

Other coincidences include but are not limited to:

1. The Tule culture which spread eastward from Northern Alaska, across the Arctic Archipelago about 1,000 years ago and then later disappeared.

2. The Cahokia culture which constructed incredible mound cities in the area of St. Louis about 1,000 years ago and then later disappeared.

3. The Great Zimbabwe culture which build city complexes in Africa about 1,000 years ago and then later disappeared.
4. The Mongol culture which invaded most of the Eurasian landmass about 800 years ago and stayed or left. In today’s Mongolia they experience winter weather conditions called (variously) “Zud”, a killing cold resulting in the deaths of Mongolians and their livestock. It seems to me that there would have to be several generations of non-Zud like conditions to allow for a horde mounted on sturdy steppe ponies.

As I said these are only coincidences and probably do not count as objective data points like Planktonic Foraminifera say, but then Planktonic Foraminifera are natural and human history just isn’t. Right?

That covers most of the Earth with the exception of South America and Europe. Of course we all now know that Europe did not experience a global MWP, just a regional one. 😉

I’ve done a very pretty reduction of the MBH98 algorithm to linear algebra (I’ve embedded this in my emulation of their algorithm and replicate all the verbal diarrhea and hundreds of lines of Fortran code in only a few lines of R.) It’s one of 10 things that I keep meaning to finalize.

I would encourage you to finalize this, it sounds very interesting.

It seems like it would be worthwhile (publishable?) in its own right independent of the whole “is MBH98 correct” debate. If it could be shown to have approximately the same “power” as MBH98 it would be (in a perfect world) heralded by the hockey team as a valuable addition to the immensely useful tools they claim to have developed.

It’s simplicity suggests it could have wider applications than the MBH98 algorithms. Perhaps it would make it possible to predict what current proxy observations should be given current temperatures (relevant to your “bring the proxies up to date” point). Perhaps all the statistical tools and knowledge about linear regression could then be applied to it and some interesting implications about confidence intervals and robustness addressed (just speculating).

]]>By: Steve McIntyrehttps://climateaudit.org/2006/01/28/rutherford-mann-et-al-2005/#comment-43056
Thu, 02 Feb 2006 06:12:06 +0000http://www.climateaudit.org/?p=513#comment-43056I’ll post up some notes on the regression module in MBH, which is a little different than anyone thinks.

In MBH98, they do a principal components analysis on 1082 temperature gridcell series. This is a different step than the tree ring step. Then they regress 1-11 temperature PCs (depending on the step) against the proxies, including tree ring PCs. In RegEM, they have a ridge regression step and they compare the selection of the ridge parameter to selecting the number of temperature PCs to retain. But at the end of the day, you still only have 22 proxies in the 15th century network – I haven’t parsed through the code yet to see what happens. It’s good that they’ve archived code, but I haven’t had time yet to work through the steps and see how the individual functions work.

]]>By: John Shttps://climateaudit.org/2006/01/28/rutherford-mann-et-al-2005/#comment-43055
Thu, 02 Feb 2006 06:02:54 +0000http://www.climateaudit.org/?p=513#comment-43055My first pass at the difference between MBH98/99 and Rutherford et al is that it’s the difference between maximum likelihood estimation and least squares. There are a lot of layers to go through so I can’t be sure at the moment. Is that really it?
]]>